- Validate description_max_length is positive (raises ValueError on 0
or negative); the prior code would have wiped descriptions to a
single ellipsis character on description_max_length=0.
- Extract filter logic into testable module-level helpers
(_apply_board_filters, _apply_stack_filters, _apply_card_filters)
and replace the dense `continue`-based loop in deck_get_stacks with
the reviewer's elif form.
- Document the truncation length quirk in the helper docstring (result
is description_max_length + 1 chars when truncation fires).
- Add 13 new unit tests covering the include/exclude flags on board,
stacks, and flat card lists, plus the new validation paths and an
explicit "description fits within limit, no ellipsis" case.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
